Chapter 12 - Cloud Classification Flashcards
What does WMO stand for
World Meteorological Organisation
x3 Cloud shapes and their development
Cumulative - vertical development
Stratiform - horizontal development
Cirrus - Ice crystals/ fine filaments
x3 Cloud levels with heights
Low - surface- 6500 ft
Middle - 6500 - 23,000 ft
High 16500 - 45000 ft
Which cloud classification do you get in low, middle and high
Low = Strato (Water droplets) Middle = Alto (mixture of ice crystals and water droplets) High = Cirro (Ice crystals)
Why is it dangerous flying in clouds with super cool ice droplets? what temperature is it at it’s worse
0 - -10. Cloud just above freezing level. no nuclei for the ice to join - a/c will ice rapidly if flown through
How many Okta in SKC FEW SCT BKN OVC
0 1-2 3-5 5-7 8
SFSBO
What is a METAR
Actual weather at the time at that place
What is a TAF
A Forecast
How do we measure cloud base?
Ceilometer
How Oktas is considered Cloud ceiling and %
Over 50% = 5 oktas/ BKN
Lowest cloud base =
Where ever the lowest reading is in the TAF/METAR
x3 High Clouds
Cirrus (Ci)
Cirrostratus (Cs)
Cirrocumulus (Cc)
x2 Middle Clouds
Altostratos (As)
Altocumulus (Ac)
x3 Low Clouds
Stratus (St)
Stratocumulus (Sc)
Nimbostratus (Ns)
What do we associate with Nimbo
Precipitation
Describe a Cirrus
Delicate filament, white, patchy
Describe a Cirrostratus
Transparent, whitish cloud with a veil-like or smooth appearance. gives halo effect
Describe a cirrocumulus
Thin, white, patchy cloud. grainy mackerel like skin.
Describe a Altostratus
Greyish / blueish cloud sheet or cloud layer
Describe a Altocumulus
White / Grey and form sheet/ layers of cloud. Larger rounded masses.
Describe a Nimbostratus
Grey/ dark cloud layer. blot out the sun - low and ragged
Steady precipitation
Describe a Stratus
Grey, layered cloud with a uniform base
Describe a Stratocumulus
Round masses, rolls. white sheet or patchy type - always has dark layers
Describe a Cumulus
Detached clouds which is dense with sharp outline
Describe Cumulusnumbus
Heavy dense cloud with huge vertical extent
Description of clouds for cumulus x5
HMCCC
Humilis - low level, fairweather below 10,000
Mediocris - low level, medium vertical extent, max 10,000
Congestus - greater vertical extent up to 25000
Calvus - vertical up to 45,000, sharp lines
Capillatus - ice crystals at top give hair like appearance
Fractus goes with
Broken appearance with St or Cu
Castellanus looks like
Acc castle like appearance
Mammatus goes with
Cu, udder like
Lenticularis goes with
Cc, Ac, Sc and has a Lens shape
For turbulence what is the difference between moderate and severe
moderate a/c in control
severe a/c can be out of control
